Galippo, a senior, is starting at middle linebacker, the position where Kennard supplanted him last year. Kennard, a junior, has moved back to defensive end. Both say they're happy with the change.

Chris Galippo once again is USC's starting middle linebacker. Devon Kennard is playing defensive end.

The experiment that had Kennard manning the middle of USC's defense last season while Galippo was shipped to the second unit and special teams is over.

Are the problems that plagued the Trojans' defense over as well?

That's their hope.

USC's issues during a disappointing 8-5 season went well beyond one key personnel move.

Kennard did an admirable job learning perhaps the most important defensive position while playing through a hip injury that required off-season surgery.

But Galippo's reinstallation as the quarterback of the defense and Kennard's return to his original position are changes that USC coaches hope will improve the much-maligned unit as the Trojans prepare for their Sept. 3 opener against Minnesota.

Last season, USC's defense ranked 84th among 120 major college teams. The Trojans were especially bad late in several games.

Asked if he made a mistake by moving Kennard from outside linebacker to the middle, Coach Lane Kiffin said, "I don't think we'll ever know for sure, based off we didn't get to see him play a full season healthy."

Monte Kiffin, Lane Kiffin's father and the Trojans' assistant head coach for defense, dismissed the notion that the move was a mistake.

"Not really, because he actually played pretty good," he said of Kennard. "I still believe he could come back and be a darn good middle linebacker."

So why not leave him there?

The answer, USC coaches said, is multilayered.

First, Galippo's often balky back appears sound as he prepares for his fifth season in the program, and Kennard seems fully recovered from surgery. They are among USC's top 11 defensive players and coaches want them on the field at the same time.

Kennard's inability to practice during spring workouts while recovering from surgery also factored in, especially because his experience at the position paled to that of Galippo, who also sat out spring practice to preserve his back.

"To play middle linebacker you need reps," linebackers coach Joe Barry said. "You need to get the looks and go through scenarios live. You can't watch them on film. You can't talk about them. You need to live the moment on the field."

The Trojans also are in need of a better pass rush after getting only 28 sacks last season, 19 from defensive linemen. With Armond Armstead's status for the season in question because of an unspecified medical issue, Kennard provides needed speed off the edge.

Kennard, a 6-foot-3, 250-pound junior, played defensive end at the start of his freshman season and then started the last four games at outside linebacker. He welcomed the shift to the middle last season and was looking forward to another year at the position.

But he described the switch back to end as "lovely" and has been leading the line's charge during training camp.

"Playing middle linebacker made me an all-around better player," said Kennard, who was fourth on the team in tackles last season. "In coverage, I'm so much better, which is going to be a great asset for my future.

"It also kind of refreshed me at defensive end. I have a new desire for it."

Kennard, the son of former NFL offensive lineman Derek Kennard, also knows recent history: Brian Cushing and Clay Matthews did turns as linebacker/defensive line hybrids during their USC careers. Both were first-round NFL draft picks.

Defensive line coach Ed Orgeron is affording Kennard opportunities to play end from a stand-up position. The transition has been smooth.

"If you tell him to correct something, he'll go to his dorm room, study it till 2 o'clock in the morning and the next day it's fixed," Orgeron said. "I don't know if I've had many defensive linemen like that."

Meanwhile, Galippo is thrilled to have regained a position he started at 13 times in 2009.

The demotion last season stung, but it also afforded the former Anaheim Servite High player an opportunity to thrive on special teams, a skill set he is confident improved his NFL stock.

Experience also had taught Galippo that the season was longer than younger teammates realize. Players rarely make it through a season uninjured. "Knowing that, I just kind of shut my mouth, continued to practice hard and I was on every special team," he said.

Galippo played as a reserve in several games and then became a starter near midseason after weakside linebacker Malcolm Smith suffered an injury. With Kennard slowed by his hip problem, Galippo started the final five games at middle linebacker.

Now, he intends to start 12 more.

"Football is a crazy game and all kinds of stuff happens," Galippo said. "You just have to keep plugging. Work hard and stay humble and things usually work out."